[quote=@Rithy]
<Snipped quote by Eisenhorn>

I suppose they arrive only after they have manually stormed every nasty trench and fortification in the way? xD
[/quote]

Add in maintaining an offensive speed that matches the timed artillery strikes (too fast and it proves friendly fire isn't, too slow gives enemies too much time to react), and it's another day in the life of the best known Siege regiments.